What IBS Does to the Brain by Emeran A. Mayer, MD

People who have irritable bowel syndrome (IBS) generally suffer... a lot. This on-again, off-again condition causes abdominal cramping, frequent diarrhea and/or constipation that is painful, disruptive and often embarrassing. As though thats not enough of a burden, you can only imagine how upsetting it is for IBS patients to hear doctors dismiss their disorder as "psychologically based."

Well, folks with IBS, your days of feeling disrespected and dismissed may be coming to an end. New research has demonstrated that people with IBS have differences in the brain that link directly to their physical troubles -- a discovery that also points to strategies that can be immediately helpful in improving symptoms.

What Imaging Showed

Using magnetic brain imaging, researchers at UCLA and McGill University evaluated differences in brain structure between a group of 55 women with IBS and a control group of 48 healthy women. (IBS affects more women than men.) The average age of the women in the study was 32, and the average length of time patients had suffered with IBS was 11 years.

Results: The study revealed distinct differences between the two groups in gray matter density. IBS patients had less gray matter in some regions of the brain and denser gray matter in others. These differences appeared in areas of the brain involving attention, emotion regulation, pain inhibition and the area where sensory information from the gastrointestinal tract is processed.

Of particular interest was the research finding about pain inhibition -- or lack thereof. It seems that IBS patients have an abnormality that may make their brains experience pain signals from the gut more intensely. There was also evidence of changes in another area that could mean pain signals from the gut were less likely to be suppressed. Though this study examined only women, the researchers said that they believe the findings to be true of men as well -- another study is underway to answer this question.

Whats the Cause?

Emeran Mayer, MD, the UCLA study author and director of the UCLA Center for Neurovisceral Sciences & Women's Health and the UCLA Division of Digestive Diseases, told me that its not yet clear whether brain abnormalities cause IBS symptoms (or some of them at least) or whether the brain changed to adapt to the chronic pain associated with IBS.

These associations may be quite complex, Dr. Mayer noted. It may be that the brains of some people have abnormal gray matter density at birth, and so they are thus predisposed to suffer pain more intensely -- for example, research has shown that anxiety correlates with gray matter changes in a particular brain region. But for others, it may be that the brains gray matter changes in response to chronically increased signals from the gut to the brain. Similar (but not identical) brain abnormalities also can be seen in patients with other chronic pain conditions, including fibromyalgia and osteoarthritis -- and, interestingly, research has shown that the brain abnormalities in patients with chronic hip pain can normalize after hip-replacement surgery. Researchers are examining these scenarios and others in their effort to ascertain what changes in the brain might link to specific patterns of IBS, such as IBS with depression or without... with constipation or without... and so on. This information may someday help identify the best therapies for individual types of IBS.

Anxious About This?

The researchers also found that patients with gray matter changes in regions of the limbic system of the brain (where emotions are generated and processed) had heightened anxiety levels -- most particularly anxiety about their symptoms, which affects a different part of the brain than generalized anxiety.

The obvious question is, can IBS patients manage their symptoms by learning to control their anxiety? Indeed they can, at least to some extent.

A growing body of research explores this treatment approach, with numerous well-controlled clinical trials, including some examining the role of the brain chemical serotonin in the digestive system (see Daily Health News July 6, 2009 "The Serotonin-Bone Mass Connection"), finding that reducing anxiety levels decreases IBS symptoms. In fact, some studies indicate that cognitive behavioral therapy (CBT) is even more effective at relieving IBS symptoms than the currently available IBS medications. Consequently, said Dr. Mayer, he "absolutely supports lifestyle approaches," including general stress management, relaxation training and diaphragmatic breathing, as part of IBS treatment.

Dr. Mayers advice is to investigate a range of activities that help reduce anxiety (such as regular exercise) along with others that help relieve it (such as mindfulness meditation). The goal should be to find activities that you enjoy and find personally effective so that youll incorporate them into your daily routine -- not only making IBS symptoms better but improving the quality of your life in general.

Source(s):

Emeran A. Mayer, MD, professor, departments of medicine, physiology and psychiatry, David Geffen School of Medicine, University of California, Los Angeles, director of the UCLA Center for Neurobiology of Stress, and codirector of the CURE: Digestive Diseases Research Center and the UCLA Division of Digestive Diseases.